Benji Marshall has opened up about the reasons behind the "hardest decision of his career", saying he had to do the right thing for himself and quit Wests Tigers at the end of the NRL season.

Marshall, 28, will walk away from the final two years of his deal with the Tigers, ending a roller-coaster 11-year association with the club .He said he owed the club a lot for making him the man he is today but had to put himself first in deciding the next stage of his career.

"I've always based my decision on what I thought was the right thing to do and what was right for everyone else," Marshall said in a video to fans on the Tigers website on Thursday. "But this decision is about me and what's right for me; I hope you can respect that. I know some people are not going to be that happy about it and some people will probably be happy to see my go. That's life. Rugby league's a game. The clubs bigger than me, the clubs bigger than everyone else and it's about making sure the club stays alive. For the time being I needed to invest in what's right for me and this decision is definitely what's best for me."

Marshall was adamant the decision was not about money, and he re-iterated his resolve to never play against the joint-venture club. "The Tigers is my home and will always be my home," he said. "Whether I'm here now and not here next year, I'm always going to support the Tigers. Hopefully I can still be involved with the club when I retire. There's no hard feeling between myself and the club. At the end of the day they did what they could within the cap to try and keep me.The decision goes far beyond money. I think you guys know that. If it was about money in the past I could have taken a lot more money and gone elsewhere back in 2008 and those years."

Marshall thanked the Tigers fans for their support and said he was confident he could prolong his time with the club beyond the final eight rounds of the regular season.

He said there was no chance he would walk out on the club early, with the NRL round-25 clash against South Sydney set to be his 200th game for the club. "I'm committed to making sure the next eight weeks are the best eight weeks I can have to make the semis," Marshall said. "I really think we're a realistic chance of making it looking at our run home. We're really going to need your support, I'm going to need your support and respect but I have to move on from this decision and so does everyone else."